View full sizeNASA / AP PhotoThis map provided by NASA shows the visibility for the transit of Venus passes in front of sun. Venus crosses the sun on Tuesday from the Western Hemisphere. Known as a transit of Venus, this won't happen again until 2117. The transit is happening during a 6-hour, 40-minute span starting after 6 p.m. EDT in the United States.

Syracuse, NY – Odds are good that cloud cover will make residents of the Syracuse area miss a rare astronomical event taking place late this afternoon.

The transit of Venus across the face of the sun begins at 6:04 p.m. EDT and continues through sunset. Venus will move between the Earth and sun then, appearing as a tiny black dot against the glaring solar disk.

Or could, if the earthly weather cooperates. Which it’s unlikely to do around Central New York.

The skies over Syracuse are expected to be 75 percent to 80 percent cloudy between 6 p.m. and sunset, according to the National Weather Service. There’s a 40 percent chance they’ll drop some rain around 6 p.m., diminishing to 20 percent by sunset.

Observers in Oswego County could catch a break, however. Skies could be around 65 percent covered over Fulton and 50 percent covered over Oswego during transit time, according to the weather service.

Venus is the second planet from the sun and Earth is the third. But tilt of Venus’s orbit relative to Earth’s is such that Venus comes directly between the Earth and sun only once or twice a century. The last transit was in 2004 and the next one won’t take place until 2117.